Project Summary Ingestive decisions play a key role in a number of human conditions including obesity, diabetes, anorexia, hypertension, and coronary artery disease. One of the most important factors regulating these decisions is the sense of taste. The gustatory cortex (GC) in mammals has been shown to be involved in taste learning and behavior, and electrophysiological and imaging studies suggest taste quality information is encoded in the activity of both specific and broadly responsive taste-activated neurons. However, it is not clear how taste quality is spatially organized across this brain area. We will use two-photon (2P) imaging to systematically map taste quality across the breadth of GC, evaluating the hypothesis that it has an overlapping organization, with likely overrepresentation of particular tastes at the anterior and posterior extremes. We will also combine 2P imaging with specific identification of cell types, accomplished by either Cre-dependent expression or retrograde labeling. Finally we will evaluate taste responses in GC following taste learning. Collectively, these experiments will shed light on how tastes are organized in this key brain area at a cellular level, and how they are modified with behavior. Aim 1 will systematically map taste responses along the anterior-posterior axis, and also with respect to dorsal-ventral location and depth. Aim 2 will compare taste responses in Thy1- expressing pyramidal cells and GAD-expressing interneurons to the greater population of all labeled cells in GC. Taste responses will also be examined in cells that project to contralateral cortex, or to amygdala. Aim 3 will investigate taste responses in GC neurons following taste aversion learning and extinction.